1. Field of the Invention
The invention is generally related to recovery boilers and more particularly to the installation of smelt spout castings therein.
2. General Background
Recovery boilers are used primarily to reclaim chemicals for reuse and to generate steam. The chemicals are reclaimed as a molten salt or smelt through openings between wall tubes in the boiler. A smelt spout is installed at each opening to allow the chemicals collecting on the floor to flow out and be collected via the spout. Due to the high temperatures involved and the corrosive nature of the chemicals being reclaimed, it becomes necessary to periodically replace the smelt spouts on the boilers. In recent years, a nozzle-shaped spout casting has been positioned between the spout and the wall tubes. The casting is designed to protect the wall tubes and smelt spouts from wear and forms a seal between the spout and the tubes. During installation of the spout casting and the spout, the spout casting has typically been held in place by a thick layer of refractory material until the spout could be installed. The spout is bolted to the wall of the boiler. The spout bears against the casting and then holds the casting in place. With this method of installation, the casting could easily be dislodged while the spout was being mounted. Also, the thick layer of refractory needed to adhere to the casting was prone to being burned away or to crumbling and thus leading to severe casting erosion. This leaves a need for a more efficient apparatus and method of installing the casting and holding it in place until the spout can be installed and bolted to the wall of the furnace.